don't focus on leaves... only the bracts / calyxes.
even those look to have some consistent amber, but only one locale pictured. Must consider entirity of what you will harvest. Can read 1000+1 opinions on what %-amber is "best" but comes down to personal preference... take a note of roughly what you estimate this time.. try a little later or earlier next time... compare what you felt and keep figuring out what you like most.
Can stagger your harvest a bit too, if you see significantly more development in top X inches.. chop that down.. riase planters or lower lights etc... keep going a few day slonger as needed. I wouldn't do this for an extended period of time for fear of stress. Takes a long time for nanners or sacs to form (4 weeks ish), so 1-2 weeks is probably not a problem?
can use something to raise up the other planters to even out canopy. if you want..